2001 YAMAHA YZ125LC oil

5-30
CHASFRONT FORK
EC553201
Inner tube
1. Remove:
9Dust seal 1
9Stopper ring 2
Using slotted-head screwdriver.
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Take care not to scratch the inner tube.
2. Remove:
9Inner tube 1
EC553311
Damper rod
1. Remove:
9Base valve 1
9Damper rod 2
NOTE:
Use a damper rod holder 3to lock the
damper rod.
EC554000
INSPECTIONEC554100
Damper rod
1. Inspect:
9Damper rod 1
Bend/DamageÕReplace damper rod.
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The front fork with a built-in piston rod has
a very sophisticated internal construction
and is particularly sensitive to foreign ma-
terial.
Use enough care not to allow any foreign
material to come in when the oil is re-
placed or when the front fork is disassem-
bled and reassembled.
Oil seal removal steps:
9Push in slowly athe inner tube just be-
fore it bottoms out and then pull it back
quickly b.
9Repeat this step until the inner tube can
be pulled out from the outer tube.
Damper rod holder:
YM-1423/90890-01423
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5-31
CHASFRONT FORK
EC554200
Base valve
1. Inspect:
9Valve assembly 1
Wear/DamageÕReplace.
9O-ring 2
DamageÕReplace.
EC554400
Fork spring
1. Measure:
9Fork spring free length a
Out of specificationÕReplace.
EC554502
Inner tube
1. Inspect:
9Inner tube surface a
Score marksÕRepair or replace.
Use #1,000 grit wet sandpaper.
Damaged oil lock pieceÕReplace.
9Inner tube bends
Out of specificationÕReplace.
Use the dial gauge 1.
NOTE:
The bending value is shown by one half of the
dial gauge reading.
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Do not attempt to straighten a bent inner
tube as this may dangerously weaken the
tube.
EC554600
Outer tube
1. Inspect:
9Outer tube 1
Score marks/Wear/DamageÕReplace.
Standard
460 mm 455 mm
(18.1 in) (17.9 in)Fork spring free length:
Inner tube bending limit:
0.2 mm (0.008 in)
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5-33
CHASFRONT FORK
5. Install:
9Spring guide 1
9Locknut 2
To damper rod 3.
NOTE:
9Install the spring guide with its cut afacing up-
ward.
9With its thread bfacing upward, fully finger
tighten the locknut onto the damper rod.
6. Install:
9Dust seal 1
9Stopper ring 2
9Oil seal 3
9Plain washer 4
9Slide metal 5
To inner tube 6.
NOTE:
9Apply the fork oil on the inner tube.
9When installing the oil seal, use vinyl seat a
with fork oil applied to protect the oil seal lip.
9Install the oil seal with its manufacture's marks
or number facing the axle holder side.
7. Install:
9Piston metal 1
NOTE:
Install the piston metal onto the slot on inner
tube.
8. Install:
9Outer tube 1
To inner tube 2.
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5-34
CHASFRONT FORK
9. Install:
9Slide metal 1
9Plain washer 2
To outer tube slot.
NOTE:
Press the slide metal into the outer tube with
fork seal driver 3.
10. Install:
9Oil seal 1
NOTE:
Press the oil seal into the outer tube with fork
seal driver 2.
11. Install:
9Stopper ring 1
NOTE:
Fit the stopper ring correctly in the groove in the
outer tube.
12. Install:
9Dust seal 1
NOTE:
Apply the lithium soap base grease on the inner
tube.
Fork seal driver:
YM-01442/90890-01442
Fork seal driver:
YM-01442/90890-01442
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5-35
CHASFRONT FORK
13. Check:
9Inner tube smooth movement
Tightness/Binding/Rough spots ÕRepeat the
steps 2 to 12.
14. Compress the front fork fully.
15. Fill:
9Front fork oil
Until outer tube top surface with recom-
mended fork oil 1.
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9Be sure to use recommended fork oil. If
other oils are used, they may have an ex-
cessively adverse effect on the front fork
performance.
9Never allow foreign materials to enter the
front fork.
16. After filling, pump the damper rod 1slowly
up and down more than 10 times to distrib-
ute the fork oil.
17. Fill:
9Front fork oil
Until outer tube top surface with recom-
mended fork oil once more.
18. After filling, pump the outer tube 1slowly
up and down (about 200 mm (7.9 in) stroke)
to distribute the fork oil once more.
NOTE:
Be careful not to excessive full stroke. A stroke
of 200 mm (7.9 in) or more will cause air to en-
ter. In this case, repeat the steps 15 to 18.
Recommended oil:
Suspension oil “01”
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5-36
CHASFRONT FORK
19. Wait ten minutes until the air bubbles have
been removed from the front fork, and the
oil has dispense evenly in system before
setting recommended oil level.
NOTE:
Fill with the fork oil up to the top end of the outer
tube, or the fork oil will not spread over to every
part of the front forks, thus making it impossible
to obtain the correct level.
Be sure to fill with the fork oil up to the top of the
outer tube and bleed the front forks.
20. Measure:
9Oil level (left and right) a
Out of specification Õ Adjust.
NOTE:
Be sure to install the spring guide 2when
checking the oil level.
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Never fail to make the oil level adjustment
between the maximum and minimum level
and always adjust each front fork to the
same setting. Uneven adjustment can
cause poor handling and loss of stability.
Standard oil level:
135 mm (5.31 in)
Extent of adjustment:
80~150 mm (3.15~5.91 in)
From top of outer tube with
inner tube and damper rod
1 1
fully compressed without spring.
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5-42
CHASHANDLEBAR
EC5B3000
REMOVAL POINTS
EC5B3100Master cylinder
1. Remove:
9Master cylinder bracket 1
9Master cylinder 2
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9Do not let the master cylinder hang on the
brake hose.
9Keep the master cylinder cap side horizontal
to prevent air from coming in.
EC5B3200
Grip
1. Remove:
9Grip 1
NOTE:
Blow in air between the handlebar or tube guide
and the grip. Then remove the grip which has
become loose.
EC5B4000
INSPECTION
EC5B4100
Handlebar
1. Inspect:
9Handlebar 1
Bends/Cracks /DamageÕReplace.
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Do not attempt to straighten a bent handlebar
as this may dangerously weaken the handlebar.
EC5B5000
ASSEMBLY AND INSTALLATION
EC5B5100
Throttle assembly
1. Install
9Grip (right) 1
Apply the adhesive on the tube guide 2.
NOTE:
9Before applying the adhesive, wipe off grease
or oil on the tube guide surface awith a lac-
quer thinner.
9Align the mating mark bon the grip (right) with
the slot cin the tube guide.
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5-43
CHASHANDLEBAR
2. Install:
9Grip cap (upper) 1
9Grip cap (lower) 2
9Bolt (grip cap) 3
NOTE:
Temporarily tighten the bolts (grip cap).
EC5B5210
Handlebar
1. Install:
9Handlebar 1
9Handlebar holder 2
9Bolt (handlebar holder) 3
NOTE:
9The upper handlebar holder should be installed
with the punched mark aforward.
9First tighten the bolts on the front side of the
handlebar holder, and then tighten the bolts on
the rear side.
2. Install:
9Grip (left) 1
Apply the adhesive to the handlebar 2.
NOTE:
9Before applying the adhesive, wipe off grease
or oil on the handlebar surface awith a lac-
quer thinner.
9Install the grip (left) to the handlebar so that the
line bbetween the two arrow marks faces
straight upward.
3. Install:
9Collar 1
9Cap cover 2
9Throttle 3
NOTE:
9Apply the lithium soap base grease on the
throttle grip sliding surface.
9Tighten the grip cap bolts temporarily without the
throttle being fixed to the handlebar.
28 Nm (2.8 m•kg, 20 ft•lb)
5MV-9-30-5C 6/19/00 1:27 PM Page 8